JP3520704B2 - Magnetic recording / reproducing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus capable of highly accurately generating a switching signal for a head arranged on a cylinder.

[0002]

2. Description of the Related Art Conventionally, as a magnetic recording / reproducing apparatus relating to a function of generating a head switching signal, Japanese Patent Application Laid-Open No. 5-6229 is known.
The one described in Japanese Patent Publication No. 1 is known. FIG. 5 is a block diagram showing a configuration relating to requirements for generating a head switching signal of a conventional magnetic recording / reproducing apparatus. In FIG. 5, 1 is a cylinder, 2 is an FG element, 3 is a PG element, 4
Is a head installed in the cylinder 1. Head 4
One set (two) is installed on the cylinder, and the head for recording or reproducing is selected by the head switching signal. 5
Is an FG signal from the FG element 2, and four pulses are output each time the cylinder 1 makes one rotation. 6 is a PG element 3
One pulse is output each time the cylinder 1 makes one rotation by the PG signal from the. Reference numeral 14 is a rising mono-multi circuit, 15 is a falling mono-multi circuit, 16 is an HSW creating circuit for outputting a head switching signal (hereinafter, HSW), 5
0 is a comparator for judging from FG signal 5 and PG signal 6 whether it is the first FG pulse in FG signal 5, 51 is the number of FG in FG signal 5 and PG signal 6 to FG signal 5/2 (here, FG number = 4) This is a comparator for judging whether or not it is the FG pulse. 52 is an H input to the mono-multi circuit 14
A value for shifting the rising timing of SW, 53 is a value for shifting the falling timing of HSW input to the mono-multi circuit 15.

FIG. 6 is a timing chart showing the operation of a conventional magnetic recording / reproducing apparatus. In FIG. 6, 22 is an internal signal of the mono-multi circuit 14, and 23 is the mono-multi circuit 1.
5 is an internal signal, and 24 is a created HSW signal. The FG signal 5 and the PG signal 6 are generated by the rotation of the cylinder 1. First FG after pulse of PG signal 6
Upon receipt of the signal, the comparator 50 determines whether the FG signal 5 is the first (0th) FG pulse, and the comparator 50 activates the rising mono-multi circuit 14. The mono-multi circuit 14 advances the set rise of HSW to the value 52 to shift, and when it matches the value 52 to shift, HS
The HSW creating circuit 16 that outputs W is instructed to output the H signal.

Next, the FG number of the set FG pulse / 2
The second (second) FG signal 6 is received, and the FG signal 5 is FG
It is determined by the comparator 51 whether it is a number / 2, and the comparator 51
The falling mono-multi circuit 15 is activated. The mono-multi circuit 15 advances to the set value 53 for shifting the fall of the HSW, and when it matches the shifted value 53,
The HSW creating circuit 16 is instructed to output the L signal.

Thereafter, this operation is repeated until the HSW signal 24
Generate.

[0006]

In the above-mentioned conventional magnetic recording / reproducing apparatus, it is required to start the mono-multi circuit starting from the first FG after PG and 1/2 of the number of FGs on the opposite side. ing. However, in the conventional method, when the positional relationship between the FG as the starting point and the head becomes distant, the amount of mono-multi that shifts becomes large, so that it is easily affected by cylinder jitter, etc., and the accuracy of HSW decreases, and in the worst case, In this case, there is a possibility that the recording pattern may not be protected.

An object of the present invention is to improve the accuracy of HSW and perform recording with a stable recording pattern.

[0008]

In order to solve this problem, according to the present invention, when the positions of the FG element and the head starting from the position of the PG element are far from each other on the cylinder, the FG closest to the position of the head. The head switching signal is created based on the pulse signal from the element.

As a result, regardless of the arrangement of the head,
The accuracy of the head switching signal can be improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first invention of the present invention is a magnetic recording / reproducing apparatus for recording / reproducing an information signal on / from a track obliquely formed on a tape by a plurality of heads mounted on a rotary cylinder. a is, the disposed on the cylinder, the position signal generating means for generating a position signal corresponding to the position of synchronization with the head in rotation, little on the cylinder
At least four or more are arranged, a speed signal generating means for generating a rotation speed signal for generating a signal synchronized with rotation, a counter reset by the position signal and incremented by the rotation speed signal, and a plurality of heads of the plurality of heads. With two mono-multi circuits that make the timing of the head switching signal,
The mono-multi circuit is operated from an arbitrary value of the counter to adjust the rising timing and the falling timing of the head switching signal, whereby the speed signal generating means arranged near the head. To generate the timing of the head switching signal.

A second invention is a magnetic recording / reproducing apparatus for recording / reproducing an information signal on / from a track obliquely formed on a tape by a plurality of heads mounted on a rotary cylinder. Position signal generating means disposed on the cylinder and generating a position signal corresponding to the position of the head in synchronization with rotation, and at least four or more on the cylinder.
Is above arrangement, the velocity signal generating means for generating a rotational speed signal for generating a signal synchronized with the rotation, a first that is incremented by the rotational speed signal is reset by the position signal
Counter, and a second counter that is reset by the position signal and has a limiter at the maximum value and that measures a predetermined clock. The arbitrary value of the first counter is the value of the second counter. Is latched, the delay amount of the head switching signal is added to the latched value, the addition result is compared with the value of the second counter, and the rising timing and the falling timing of the head switching signal are adjusted. As a result, the timing of the head switching signal is generated from the speed signal generating means arranged at a position close to the head.

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram showing a configuration of a magnetic recording / reproducing circuit according to Embodiment 1 of the present invention. In FIG. 1, 7 is a counter that resets every rotation of the cylinder 1 and counts the FG signal 5 (FG counter), 8 is an FG value that serves as a reference for rising of HSW, and 9 is an FG that serves as a reference for falling of HSW. Value, 10 is a comparator that compares the count value of the counter 7 with the FG value 8 that serves as a reference for the rise of HSW, and 11 is the count value of the counter 7 and HS.
A comparator for comparing the FG value 8 which is a reference for the fall of W, 12 is a value for shifting the rise of HSW, and 13 is a value for shifting the fall of HSW. The same components as those of the conventional example shown in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.

Further, 2 is F as a speed signal generating means.
The G elements and 3 are PG elements as position signal generating means, and are respectively mounted on the cylinder 1. Figure 2
3 is a timing chart showing the operation of the present embodiment. In FIG. 2, 21 is the value of the FG counter 7,
22 is a signal indicating the internal operation of the mono-multi circuit 14, 23
Is a signal indicating the internal operation of the mono-multi circuit 15.

The rotation of the cylinder 1 causes the FG
A signal 5 and a PG signal 6 are generated. That is, in the configuration of the cylinder 1 of FIG. 1, the PG signal 6 outputs one pulse each time the cylinder 1 makes one rotation, and the FG signal 5 outputs the FG element 2
Since there are four, four pulses are output. The FG counter 7 is reset by the first FG signal pulse after the pulse of the PG signal 6. After that, it is incremented each time the FG signal comes. Therefore, the counter value 21 of the counter 7 is
Repeat 0, 1, 2, 3, 0, 1, ...

Comparator 1 for comparing the count value 21 of the counter 7 and the FG value 8 which is the reference for the rise of HSW.
0 is the count value of the counter 7 and the reference FG value 8
When the two coincide with each other, the rising mono-multi circuit 14 is activated. In the example of FIG. 2, the reference FG value 8 is “1”.
Shows the case. The mono-multi circuit 14 is the comparator 1.
When the output of 0 starts, the rise of the set HSW is advanced to the shift value 12, and when it matches the shift value 12, the HSW creation circuit 16 that outputs the HSW is instructed to output the H signal. To do.

Next, the count value 21 of the counter 7 and HS
The comparator 11 that compares the value 9 of the FG that serves as the reference of the falling edge of W has the count value of the counter 7 and the FG that serves as the reference.
When the value of 9 matches, the mono-multi circuit for falling 15
To start. In the example of FIG. 2, the case where the reference FG value 9 is “3” is shown. The mono-multi circuit 15 is activated by the output of the comparator 15, proceeds to the set value 13 of the rising of the HSW, and when it matches the value 13 to be shifted, outputs an L signal to the HSW creating circuit 16. Instruct them to take it out.

Thereafter, this operation is repeated to generate the HSW 24. As described above, according to the present embodiment, the reference FG value 8 given to the comparators 10 and 11,
By setting 9 only, the HSW can be generated based on the pulse from the FG element 2 closest to the head 4. Therefore, from the arrangement of the head 4 and the arrangement of the FG element 2, the optimum FG element 2 can be obtained.
Since it is possible to select the
Can be obtained. Also, for head arrangements other than the opposed head arrangement shown in FIG.
Only by changing 9, it is possible to deal flexibly.

(Second Embodiment) FIG. 3 is a block diagram showing a configuration of a magnetic recording / reproducing circuit according to a second embodiment of the present invention. In FIG. 3, 31 is the first F after the PG pulse.
A time measurement counter activated by G, 34 is a value obtained by latching the value of the counter 31 with the output of the comparator 10, 35 is a value obtained by latching the value of the counter 31 with the output of the comparator 11, and 36 is a value of the latched counter 31. An adder for adding the value 34 and a value 12 for shifting the rise of HSW, 37 is an adder for adding the value 35 of the latched counter 31 and a value 13 for shifting the fall of HSW, and 38 is a counter 31 40, a comparator 39 that compares the count value 38 of the counter 31 with the adder 36, and outputs a rise timing of the HSW to the HSW creating circuit 16 when they match, 40
Compares the count value of the counter 31 with the adder 37,
It is a comparator that outputs the HSW fall timing to the HSW creation circuit 16 when they match. The same components as those of the conventional example shown in FIG. 6 or the first embodiment shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 4 is a timing chart showing the operation of this embodiment. The FG signal 5 and the PG signal 6 are generated by the rotation of the cylinder 1. After the pulse of the PG signal 6, the FG counter 7 is reset by the first FG signal 5. After that, it is incremented each time the FG signal 5 arrives (every time it rises). Further, the time measuring counter 31 is also reset at the same time as the FG counter 7 and is incremented every unit time thereafter. Here, the unit time of the counter 31 is obtained from the accuracy required for the head switching signal 24, and the accuracy becomes higher if the unit time is shortened.

The count value 21 ("0" ...
"3") and the value of FG which is the reference for the rise of HSW 8
Are compared by the comparator 10, and when the count value 21 of the counter 7 is "1", it coincides with the reference FG value 8 "1", and the value of the counter 31 is latched at that timing. The latched value 34 is sent to the adder 36, added with the shift value 12, and input to the comparator 39. The comparator 39 compares the output of the adder 36 with the count value 38 of the counter 31, and when the two values match, instructs the HSW creating circuit 16 to output an H (high) signal.

Next, the count value 21 of the counter 7
(“0” to “3”) and the FG value 9 serving as a reference for the rise of HSW are compared by the comparator 11, and the count value 21 of the counter 7 and the reference FG value 9 “3”. And the counter value of the counter 31 is latched at that timing. The latched value 35 is sent to the adder 37, is added to the shift value 13, and is input to the comparator 40. The comparator 40 compares the output of the adder 37 with the count value 38 of the counter 31, and when the two values match, instructs the HSW creating circuit 16 to output an L (low) signal.

Thereafter, this operation is repeated to generate the HSW 24. As described above, according to the present embodiment, the reference FG value 8 given to the comparators 10 and 11,
By setting 9 only, the HSW can be generated based on the pulse from the FG element 2 closest to the head 4. Therefore, from the arrangement of the head 4 and the arrangement of the FG element 2, the optimum FG element 2 can be obtained.
Since it is possible to select the
Can be obtained. In addition, in the head arrangement other than the opposed head arrangement shown in FIG. 3, the reference FG value of 8,
Only by changing 9, it is possible to deal flexibly.

Further, in the present embodiment, the timing of the head switching signal 24 is generated by the counter 31 instead of the mono-multi circuit, so that the head switching signal 24 with stable accuracy can be obtained.

[0024]

As described above, according to the present invention, it is possible to improve the accuracy of producing the head switching signal even when the starting position of the FG element and the head are far from each other, and as a result, stable recording / reproducing is performed. It can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a timing chart showing the operation of the magnetic recording / reproducing apparatus.

FIG. 3 is a block diagram showing a configuration of a magnetic recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 4 is a timing chart showing the operation of the magnetic recording / reproducing apparatus.

FIG. 5 is a block diagram showing the configuration of a conventional magnetic recording / reproducing apparatus.

FIG. 6 is a timing chart showing the operation of a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

1 cylinder 2 FG element 3 PG element 4 heads 5 FG signal from FG element 2 6 PG signal from PG element 3 7 counter 8 FG value that becomes the reference for the rising of HSW 9 FG value that becomes the reference of HSW fall 10, 11 comparator Value to shift the start of 12 HSW 13 HSW value to shift the fall 14, 15 Mono-multi circuit 16 Head switching signal creation circuit 24 head switching signal

Claims (2)

(57) [Claims] 1. A magnetic recording / reproducing apparatus for recording / reproducing an information signal to / from a track obliquely formed on a tape by a plurality of heads mounted on a rotary cylinder, the magnetic recording / reproducing apparatus being arranged on the cylinder. Position signal generation means for generating a position signal corresponding to the position of the head in synchronization with rotation, and at least four or more arranged on the cylinder, and a speed signal generation for generating a rotation speed signal for generating a signal synchronized with rotation. Means, a counter that is reset by the position signal and incremented by the rotation speed signal, and two mono-multi circuits that generate the timing of the head switching signals of the plurality of heads. Each of the multi-circuits is operated to adjust the rising timing and the falling timing of the head switching signal. Characteristic magnetic recording / reproducing device. 2. A magnetic recording / reproducing apparatus for recording / reproducing an information signal to / from a track obliquely formed on a tape by a plurality of heads mounted on a rotating cylinder, the magnetic recording / reproducing apparatus being arranged on the cylinder. Position signal generating means for generating a position signal corresponding to the position of the head in synchronization with rotation, and a plurality of at least four or more are arranged on the cylinder,
Speed signal generating means for generating a rotation speed signal for generating a signal synchronized with rotation, a first counter reset by the position signal and incremented by the rotation speed signal, and a maximum value reset by the position signal A second counter which has a limiter and measures a predetermined clock, latches the value of the second counter with an arbitrary value of the first counter, and delays the head switching signal to the value of the latch. Is added, the addition result is compared with the value of the second counter,
A magnetic recording / reproducing apparatus, characterized in that a rising timing and a falling timing of the head switching signal are adjusted.